In the data center and high performance computing market, there has been growing demand for high data transfer rate and increased bandwidth. This market demand has resulted in a technological transition from copper to fiber optic transceivers (combined transmitters and receivers), including the implementation of on-board optics and fiber optic backplane connectivity.
Currently, most fiber optic transceiver modules are configured with either receptacles or fixed length pigtails. In order to reduce overall system cost and link loss, there is a trend among system and module manufacturers to configure transceiver modules with pigtails with lengths ranging from 1 meter to 30 meters. Although this connectivity is advantageous for the end-user, integrating long pigtails into a transceiver module can be difficult in manufacturing and results in inventory management challenges for the manufacturer.
Currently, there are two main approaches. A first approach is to build transceivers with discrete pigtails having lengths from 1 meter to 30 meters. This approach requires the manufacturer to stock cable assemblies with discrete lengths from 1 meter to 30 meters with a fiber optic connector, such as an MPO on one end and a v-groove block or lensed connector, such as a PRIZM-LT, on the other end. The manufacture will then attach the cable assembly v-groove block or lensed connector onto the optical engine of the module PCB while managing these variable length cable assemblies. This requires the manufacturer to develop complex handling and assembly fixtures that can compactly store these variable length cable assemblies during the manufacturing process. Additionally, the manufacturer must stock transceiver modules with multiple pigtail lengths to meet an unknown customer demand.
A second approach is to build transceivers with a 1 meter cable stub. The manufacturer would then splice the pigtail of required length onto the 1 meter stub of the transceiver. This approach simplifies the module manufacturing process and reduces the manufacturer's inventory risk. However, this approach also requires the manufacturer to build up a protective cover over the splice point. In particular, commercially available in-line splices typically have an outer diameter that is much larger than the cables they are joining (greater than 6 mm for a 3 mm outer diameter cable) and have a stiff length greater than 100 mm. The size of these inline splices makes it challenging for the end-user to route the splice point within the data center fiber management hardware. Additionally, these inline splice solutions are difficult to assemble, being best suited for factory assembly.
Accordingly, improved assemblies for interconnecting fiber optic cables with transceiver modules are desired in the art.